In recent years, single use or disposable containers for the storage, transport and serving of various comestibles, whereby the containers are constituted from a thermoplastic material, such as foamed polystyrene or the like, have come into widespread use in various institutions, so called "take-out" restaurants and "fast-food" retail establishments. These containers generally incorporate a tray member adapted to receive the comestibles, and a superimposable cover structure hingedly connected to the tray member to enable the contents of the container to be sealed during transportation and storage, and in many instances allows for maintaining specific temperature conditions of the container contents. The widespread acceptance of such containers by consumers has lead to their development to incorporate a plurality of compartments for the discrete storage and/or serving of different types of food items; such as a main course from one container compartment, a vegetable or the like from another container compartment, and possibly a dessert or salad from a said in a further container compartment, or the like. Containers of that type are extremely popular inasmuch as they allow for the storage and serving of entire meals therefrom without having to resort to an array of separate containers for serving the individual food items or comestibles of a meal.
Among the problems which have been encountered in the storage of food items in a single container having a plurality of compartments, each of which is intended to receive a different type of food item or comestible, are the difficulties in maintaining such items separated from each other during the storage and transport of the containers from one location to another, such as from the retail or "fast-food" establishment towards a location where the container contents are to be consumed, inasmuch as this may quite frequently entail tipping and shaking, or even inverting of the container, thereby causing the compartmented container contents to intermingle and possibly rendering the foods unattractive if not completely unpalatable to a prospective consumer.
In order to ameliorate the problem of spillage of food items from one compartment to another when the container is in a closed condition and while it is being transported or moved about in different orientations, structure has been proposed in the form of either an internal lid closing off the compartments beneath the cover or, alternatively, the cover portion of the container itself may be provided with suitable depending wall or rib structure which, when the cover is closed over the tray member will contact the upstanding walls of the compartments in generally sealing engagement so as to inhibit foods contained in the individual compartments from commingling with the contents of other compartments in the container. This, in effect, will considerably enhance the versatility of such containers and render them adaptable for the storage, conveyance and serving of different types of foods from compartments in the same container. Moreover, the container may also be constituted from a suitable material, such as foamed thermoplastic, as polyethylene, polystyrene or the like, which will ensure that the food items contained in each of the various compartments maintain their respective temperatures. For instance, one compartment may contain hot food, whereas an adjoining compartment may contain a cold food item, with each of the compartmented foods being essentially in a thermally sealed-off relationship relative to the other compartments of the container. Additionally, the material of the container may lend itself to use in a microwave oven by being constituted of a material which is transparent to microwave energy, thereby enabling the heating of the food items while in the closed container, thereby again rendering the container contents more palatable and attractive to a prospective consumer.
Numerous containers of the type described herein are currently being marketed for purposes of storing, heating and discretely serving a plurality of food items or comestibles separately stored in various compartments of such containers.
For example, U.S. Pat. No. 4,081,646, discloses a multi-compartmented container enabling the storage of different types of foods in compartments which are separated from each other by formations of upstanding wall portions in a tray member. A cover member which is hingedly connected to the compartmented tray member containing the food items includes depending ribs which are in the form of depending walls engaging into the respective compartments so as to prevent contact between the compartment walls and the foods, the latter of which are generally in a frozen condition. Thereafter, the container is adapted to be exposed to microwave energy in a microwave oven while in an inverted condition, preferably within an outer receptacle incorporating wall portions which are transparent to microwave energy so as to enable heating the food, and then the container is reversed into its upright position, the cover member lifted open and removed from the container. This will enable the food items to be maintained in the compartments without contacting the wall surfaces thereof in a supposedly unsightly manner, thereby rendering the contents more palatable to a consumer. However, the construction of a multi-compartmented container as described in this patent is relatively complex and necessitates an extremely close accuracy in the dimensioning of the depending wall structure of the cover to enable to sealingly engage the inner surfaces of each of the tray compartments to prevent leakage of any sauces or gravies between and contact with the cooperating wall structures. Consequently, the container structure is extremely expensive and complex in manufacture and renders the containers uneconomical from the standpoint of mass production and disposable applications in so-called "take-out" or "fast-food" retail operations.
U.S. Pat. No. 4,653,685, describes a dual compartmented sandwich package in which wall structure provided on a container cover portion will separate tray compartments so as to permit hot and cold foods contained in each respective compartment to be maintained in a separated condition.
Other containers which enable the separation of foods and similar types of items contained therein are also known. For example, U.S. Pat. No. 4,234,097 discloses a serving plate set having two similar receptacles which in one form is separated by a sealing member that segregates the receptacle contents, such member also being of a plate-like configuration and which in another form employs the two receptacles to create a closured container.
U.S. Pat. No. 4,440,303 relates to an improved insulated tray having both of its top and bottom surfaces configured so that either may receive food articles. The configuration is such that the trays may be stacked one upon the other in a wide variety of configurations. When so stacked, the depressions in the upper tray serve to provide a closure for the depressions in the lower tray.
U.S. Pat. No. 4,545,487 relates to a food serving tray which has a hood shaped to define a generally planar upper surface along with a downwardly depending first marginal skirt. A generally planar lid has an upwardly projecting second marginal skirt that is bonded to the first skirt. A food support is also of generally planar shape and has a downwardly depending third marginal skirt that is bonded to an upwardly projecting fourth marginal skirt of a likewise generally planar base. The lid is indexed so as to lie in mating relationship atop the support. A liner desirably covers the support.
Although these publications describe multi-compartmented containers of various types, none of these are actually adapted for use in so-called "fast-food" operations enabling their economical applications and ready disposability after a single use by a consumer. U.S. patent application Ser. No. 07/555,228, filed on Jul. 19, 1990, the inventors of which are also the inventors of the present invention, discloses such a container. The container described therein, comprises a tray member having a plurality of compartments separated by upstanding wall portions, a bottom wall structure and a peripheral sidewall forming an encompassing tray rim; a cover member hingedly joined to the tray member along a portion of the tray rim, the cover member having a peripheral depending wall structure engageable with the tray rim to form a closed container arrangement; and depending rib means formed in the cover member engageable with the surfaces of the upstanding wall portions of the tray compartments for sealing the compartments the container is in the closed condition. In a preferred embodiment of the container disclosed in Ser. No. 07/555,228, the cover member and tray member each are provided with peripheral flange portions, the tray member having a peripheral recess formed in its flange portion for the purpose of receiving the flange portion of the cover member in the closed condition of the container so as to assist in providing a sealed container structure. In a more preferred embodiment of the compartmented container of Ser. No. 07/555,228, the flange portion of the cover member is provided with tabs along an edge opposite the hinged connection between the tray and cover, with slit means in the flange portion of the tray member cooperatively engageable by the tabs for releasably latching the container in a closed condition.
While the container of Ser. No. 07/555,228, provides an effective structure, addressing the problem of food item spillage between container compartments when closed and moved about, and is particularly well-suited for use in fast-food operations, a need still exits for a container which provides enhanced sealing characteristics for use in fast-food operations.